In the US alone, over 500,000 people die annually from SCA. Many of these victims have no prior warning of heart disease, and 70% die outside the hospital. The most common electrophysiologic mechanisms leading to SCA are tachyarrhythmias such as VF or VT, and the only treatment for this victim is to provide an immediate, high-energy electric shock through the heart. Minimizing the time to first shock is critical since, the survival rates after cardiac arrest decrease by approximately seven to 10 percent every minute that defibrillation is delayed. If a shock is not applied within 10 minutes, the chances of resuscitation are almost zero.
Survival from sudden cardiac arrest critically depends on timely resuscitation. Chances for survival from sudden cardiac arrest caused by VF or VT will be achieved if Automated External Defibrillators (AED) were made more widely available within the community, ensuring that patient who had cardiac arrest in the out-of-hospital setting will be treated as soon as possible by this life saving technique.
It is estimated that approximately 50,000 of these deaths could have been prevented if an Automated External Defibrillator (AED) had been available for immediate use at the time of the emergency, and someone had initiated the Cardiac Chain of Survival.
The American Heart Association stresses the importance of creating “heart save community” by providing quick access to AEDs which are available to the public at airports, malls, sport stadiums and leisure centers, thus creating “heart save environment”.
Commercially available AED systems were designed for use by people with no medical training (lay rescuers) and by health care providers. The AED system is attached to the patient's chest and it is used to analyze the patient's heart rhythm. If VF is detected, the AED delivers an electric shock to get the heart beating again. Such units have been placed in public locations such as airports, airplanes, and theaters. However, to date there is no device specifically designed for personal/laymen use.
The person operating an AED known in the art is potentially at risk of getting an electrical shock if he is in contact with the patient connected to the shocking electrodes. This risk increases when an untrained person is operating the AED.
U.S. Pat. No. 5,700,281, issued on Dec. 23, 1997, describes the use of prompts to guide a user in assisting an SCA victim. An AED is described to be used by an untrained user. Utilizing the electrode packaging above, the AED monitors the state of the AED and the stage of a rescue. In particular, at least five stages of a rescue are monitored. These include: 1) rescue initiated; 2) preparing victim; 3) applying electrodes; 4) AED in use; and 5) rescue completed. The '281 patent uses impedance values between the electrode pads to determine the stage of a rescue attempt in order to prompt and thereby guide the user.
United States Patent Application 20040143297, to Ramsey, Maynard III; titled “Advanced automatic external defibrillator powered by alternative and optionally multiple electrical power sources and a new business method for single use AED distribution and refurbishment”; filed Jan. 21, 2003; describes an AED being powered by 120/240 VAC electrical power alone, being powered by external DC power alone, or any in combination with or without internal-integral battery power, and further an AED access service business method for sales of access to AEDs. The AED, in addition to the defibrillator circuitry comprises a long, tangle free power access cord to be plugged into an external source of AC or DC power and optionally, additional sets of body surface and alternative electrodes positioned in the esophagus and/or heart. The AED has additional advanced capabilities including the ability to deliver rapid sequential shocks through one or more sets of patient electrodes, and the optional mode of shock delivery whereby the shock is delayed while the AED continues to analyze the patients ECG waveform and delays the defibrillation shock or sequence of shocks until the ECG analysis indicates conditions are optimum for successful defibrillation.
Currently most known AED systems are big and heavy to carry and are available for use by the public at airports, malls, sport stadiums and leisure centers. The AED systems are not designed for personal use; they do not include any communication system; and none of them use a remote control for the safety of the person who is using them.
The FRED Easyport AED from Schiller weighs 490 grams. According to the manufacturer, the device intended for use by basic life support responders, healthcare professionals, such as doctors, paramedics and public service staff. Additionally, at-risk heart patients could carry this device for their own rescue after they and their family are trained in its use.